[Feature Request] Group Chat Multi-User Support: Permission isolation, user identification, and privacy controls

[cc3wangdehai-hue]

Problem

Current platform has limited group chat support:

1. User identification: Hard to accurately identify which user sent a message in group chats
2. No permission isolation: No user-based access control in shared agent sessions
3. Context confusion: Multi-user conversation contexts get mixed together
4. Privacy risk: Users may inadvertently see each other"s sensitive information
5. No audit trail: No record of who triggered what action

Proposed Solution

1. User Identification Layer

• Support @mention for explicit user addressing
• User ID embedded in every message metadata
• Display name mapping with unique internal IDs
• Guest/anonymous user handling

2. Permission System

Role	Capabilities
Admin	Full control, manage members, configure agent
Member	Use agent, access shared context
Guest	Read-only, limited queries

• Per-user file access control (owner-only, shared, public)
• Operation-level permissions (who can run bash, who can send email)
• Admin can restrict sensitive operations to specific roles

3. Context Isolation

• Shared context: Common knowledge visible to all
• Private context: Per-user memory and preferences
• Threaded conversations: Sub-conversations within the group
• Context merging strategy: how shared + private contexts combine

4. Privacy Controls

• Sensitive operations require explicit confirmation from the initiating user
• SECRET.md scoped to individual users, not shared
• Auto-redaction of other users" private data in responses
• Session-level privacy mode (strict/normal/open)

5. Audit Logging

• Record: who, what, when, result
• Searchable by admin
• Export for compliance
• Retention policy configurable

Impact

• Enables team/enterprise collaboration scenarios
• Privacy compliance for multi-user environments
• Extends platform use cases from personal to organizational
• Foundation for enterprise-grade access control

Priority

P2 (Medium) - Critical for enterprise and team scenarios